A facial expression is a visible manifestation of the affective state, cognitive

activity,intention, personality, and psychopathology of a person (Fasel et al., 2003). Facialexpressions are natural means of communications between humans. By looking at thefacial expression of a human face the emotional state of that person can be understood.

With the advancement in the field of face recognition and face detectionand theincreased availability of relatively cheap computer power(Turk et Al., 1991), there hasbeen an increasing interest in the study of automatic facial expression recognition

(AFER)

in the last decade. While human beings can easily interpret facial expressions, itis a challenging task for computers to interpret the latter. An AFER system is one whichcan automatically determine the expressions of a particular user.

and an additionalexpression “sleepy” are used.The proposed system is developed using the fourcomponents of theAFER system, as follows:

Face detection

involves locating the face from an image or video stream

from a webcamor camera.

Here

Face Detection

is

carried out

using Local Successive Mean QuantizationTransform (SMQT) Features and Split Up Sparse Network of Windows (SNOW)Classifier developed by Mikael Nilsson, NordbergJorgen and Ingvar Claesson(Nilssonet al., 2007).

expressionsand recognized the emotion, itcan simulate an unknown data. If this recognition result corresponds to the true emotionof the user, then the recognition result is said to be correct.

Two facial expressions databases were used to train the system and it was found that theaccuracy of the system was higher using the JAFFE database than MMI.The highestrecognition rate for the JAFFE facial expressions on static images was 85.7 % and at real-time 56%. Whenintegrated withtheDrowsy Driver Alert Interface (DDAI), the

overallaccuracy of the system was acceptable, about 60%. The system was also tested forimages with occlusions with rather good results.

Though the system yielded good performance, some expressions were confused witheach other e.g. if a person is surprised with the mouth open, the identified expression isthat of ‘happiness’.

References

Ekman, P., Friesen, W. V.,“Constants across cultures in the face and emotion”,